Everything’s up in the air. This article highlights what is known, airs details on solutions suggested, but no conclusions are made as Tesla grapples with multiple issues.

Speaking of aluminum, molten aluminum spilled and sent three workers to the hospital Wednesday. This is on top of Tesla losing so much stock value, and below-expectations Q3 earnings.

Tesla’s Model S sedan has wowed reviewers, aced crash tests, invoked great admiration from fans, but within five weeks two remarkably similar encounters with road debris in Washington and Tennessee resulted in serious fires.

Whether the Oct. 2 and Nov. 6 incidents will prompt a recall is still being determined, but according to the executive director of an influential non-profit automotive safety group in Washington, D.C., it should if investigators prove both fires were caused by battery compartment punctures.

And it does appear this could be the case. In both incidents, an 85-kwh Model S was traveling on a highway, and both drivers reported striking sturdy metal objects.

Just The Facts

The Model S uses high capacity 18650 lithium-ion cells supplied by an internal arm of Panasonic called the Automotive & Industrial Systems Company.

Tesla did not respond to our inquiry for this story, but in the batteries’ raw state, their chemistries are believed to be anywhere from mildly to much more flammable than batteries in the Chevy Volt or Nissan Leaf, for example.

According to Altairnano engineer and Senior Director of IP & Technology, Jay Akhave, Tesla has the highest energy in its packs which he estimated at 146 watt-hours per kilogram.

Exactly how combustible these are compared to li-ion batteries in mainstream cars mentioned is not exactly clear, but Tesla Chairman Elon Musk minimized their fire potential compared to gasoline cars in a blog post Oct. 4.

“In contrast, the combustion energy of our battery pack is only about 10-percent of the energy contained in a gasoline tank and is divided into 16 modules with firewalls in between,” said Musk. “As a consequence, the effective combustion potential is only about 1-percent that of the fuel in a comparable gasoline sedan.”

Model S battery packs also include fire-retardant gel, and protecting the underside is a quarter-inch-thick aluminum cover.

In his post following the first fire, Musk implied damage believed to be caused by a curved section that fell off a semi-trailer was an anomaly:

“The geometry of the object caused a powerful lever action as it went under the car, punching upward and impaling the Model S with a peak force on the order of 25 tons,” said Musk. “Only a force of this magnitude would be strong enough to punch a 3-inch diameter hole through the quarter-inch armor plate protecting the base of the vehicle.”

Musk said government records show Americans drive about 3 trillion miles per year, which “equates to 1 [gas-powered] vehicle fire for every 20 million miles driven, compared to 1 fire in over 100 million miles for Tesla.

“This means you are 5 times more likely to experience a fire in a conventional gasoline car than a Tesla!” concluded Musk, “For consumers concerned about fire risk, there should be absolutely zero doubt that it is safer to power a car with a battery than a large tank of highly flammable liquid.”

But five weeks after that deduction, another fire almost like it happened in Smyrna, Tennessee.

The driver – who wrote a testimonial saying he felt safe and the car saved his life – said he ran over a three-ball trailer hitch and this is believed also to have ruptured the battery.

“I felt a firm ‘thud’ as the hitch struck the bottom of the car, and it felt as though it even lifted the car up in the air,” wrote Juris Shibayama, MD. “My assistant later found a gouge in the tarmac where the item scraped into the road. Somewhat shaken, I continued to drive.”

Was this another anomaly?

The National Highway Transportation Safety Administration last reported it is talking to the Tennessee Highway Patrol, and offered no further info when asked yesterday.

“NHTSA is in close communication with Tesla and local authorities gathering information about the incident to determine if additional action is necessary,” it said.

Helpful Suggestions?

Among remedies suggested by Tesla fans are a “cow catcher” like a railroad train would use to clear debris, or an entire redesign of the underbody shielding outlined in an article written by a Model S owner for Green Car Reports.

Such suggestions even from the sympathetic may show why those less sympathetic are sitting back wondering if Tesla is innocent until proven guilty – or worse, guilty until proven innocent.

Not counting a recent Mexico Model S fire that happened under different circumstances, what has seemed apparent to observers in both U.S. fires is:

1) The battery pack’s fire protection has so far worked well enough to let cars come to a stop and occupants escape safely.
2) Once set on fire, the cars still burned to a crisp before the fires were contained – and Washington firefighters showed first responders may not know how to extinguish the EV blaze as fast as possible
3) The Achilles’ heel appears to be the shielding Musk said was so robust.

Not An Outlier?

Yesterday in a phone interview, Clarence Ditlow, executive director of the Center for Auto Safety in Washington said he has doubts about the odds of two similar incidents in quick succession for a car that only has 19,000 units on the road.

The CAS was founded in 1970 by Consumers Union and Ralph Nader and has frequently challenged NHTSA in court on issues, while in other rulings siding with it, and has long played an influential role in consumer safety.

Characteristically tight-lipped NHTSA has said nothing new lately, but Ditlow said if the battery shielding in Tennessee failed and resulted in fires, the answer is clear.

“One road-debris-caused fire may be an outlier, but two is not. In other words, I would not expect to see two road debris fires in such a small volume vehicle,” said Ditlow.

Ditlow added that the 5-foot-wide, 9-foot-long underside is tantamount to the proverbial barn door.

“You clearly have a large flat target. So the potential for road debris hitting the vehicle … is higher than in, say a gas-tank vehicle,” said Ditlow suggesting a vulnerability with the Model S compared to internal combustion cars that Musk did not.

Further, “road debris is a common hazard” he said, and odds are it will happen again.

Conservatively figuring 10,000 miles driven per year by owners of 19,000 Model S sedans now on the road equals 190 million road miles annually driven, and this is increasing.

“The fact that you had two impacts shows it’s not an exceedingly rare event like being hit by a meteor so you need to upgrade the shied,” said Ditlow adding investigators still must state the cause for the record but looking ahead should this be the case, added, “Most shields that are genuinely designed for road debris are made of steel.”

This would mean a recall would be in order, he said.

“And I understand the issue of weight on an EV,” he said. “But if an aluminum shield is not going to do the job, you have to get something that is.”

Ditlow said many light-duty trucks like Jeeps use one-eighth-inch steel, and suggested this could work for Tesla’s large flat, 4,800-pound or so car riding little more than five inches off the pavement.

He also acknowledged more data would be needed for a precisely engineered solution.

Steel? On a Tesla?

The bumpers on a Model S are about the only steel you’ll see on its elegant aluminum-intensive skateboard chassis.

According to Michigan-based steel industry executive, Ron Krupitzer, automotive engineering to encounter all likely underside crash events is a lot like evaluating crash-impact data to engineer a bumper.

As vice president for automotive applications for the Steel Market Development Institute, a business unit of American Iron and Steel Institute, Kruptizer says he has a team that regular creates solutions for automotive applications.

Steel is three-times denser than aluminum, and while heavier, he said much less of it could be used to create a stronger shield with comparable weight to aluminum.

A steel sheet the same square area as a quarter-inch-thick aluminum sheet would be only one-twelfth of an inch thick to weigh the same. However, steel’s tensile strength and puncture resistance can be so high, it might not take much – and this also shows the present aluminum “armor” under a Model S is only equal to one-twelfth of an inch, or .083-inch-thick steel.

Unknown is the exact metallurgy of Tesla’s armor, however, but good, better, and best steel is available too.

Krupitzer added his family includes major Tesla fans, he’s followed the issues, and has been approached by other reporters on the topic already.

He said it would be interesting to build a rust-resistant shield that meets critical weight requirements by using less material, and offers far more effectiveness.

“I’m confident we could have a steel selection that’s at least four- to five-times stronger and even more,” said Kruptizer.

“If Elon wants to work with the North American Steel Industry so we can obtain the model data for the underbody package we could work with him in designing a successful steel skid plate,” he said.

Or, as Green Car Reports mentioned, in question are design patents Tesla already holds for a more robust “ballistic shield” with a crush zone built in.

It’s unclear whether this aluminum and carbon fiber design has already been utilized or is waiting in the wings, said the report.

No Conclusions Yet

A recall imposed by NHTSA could however create that need. Musk was recently quoted saying “there’s definitely not going to be a recall” but as Bloomberg and several other articles quickly noted, “it’s not up to him.”

Presently federal authorities are having to apply criteria to a car not quite like any they’ve designed protocols for.

Forbes cited Allan Kam, a former senior enforcement attorney with NHTSA, who said investigators must assess whether a component is failing under foreseeable circumstances, and whether it’s safety-related.

On Tuesday Musk said the dialogue is ongoing.

“We literally are in constant contact with them,” said Musk. “NHTSA has real problems to deal with where people die or are seriously injured. Their time is preoccupied with that, not with fictional issues created by the media.”

This is true, but also fiction-free is questions do remain and not just in the minds of dispassionate watchers, but even among Tesla’s most ardent fans.

But not all of them. Others say demands for safety can be frothed to excess and side with Elon, such as a Volt-owning plug-in car fan and engineer on the GM-Volt forum who goes by “kdawg.”

“There are few accidents compared to ICE cars. The people were able to control their cars and exit them. No deaths. And the amount of energy stored in the battery is only a fraction of that in a gasoline tank,” he said. “Should Tesla make a beefier plate for the bottom of their car? I’m indifferent. It’s sort of how I felt when GM added that extra plate on the Volt’s battery due to side impacts. As an engineer, you can’t protect for 100-percent of possible scenarios … Until then, when is enough enough?”

This entry was posted on Friday, November 15th, 2013 at 5:55 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

COMMENTS: 143

1

+10

James McQuaid Says

Nov 15th, 2013 (6:31 am)

“Tesla did not respond to our inquiry for this story”

This speaks louder than anything they might have said. Musk’s personality, which has driven this company to success, may also turn out to be its downfall.

I think the middle ground in all of this, is a voluntary recall similar to what GM did for the Volt. That way, if anyone actually does feel unsafe, they can get an extra plate of metal added for free; and the other 99% can keep on driving

It also would minimize costs to Tesla and be a sign of good faith, whether “a fix” is warranted or not.

The lowering of the Model S during highway speed does increase the possibility of hitting an object rather than passing over it. The lingering question is if “catching” the object with a modification and preventing it from passing under the vehicle is a better idea? The frustration is thinking what damage that may cause. Would debris be pushed into the path of other vehicles? IMHO, anything lower than the existing vehicle bottom would catch more debris and increase the need to pull over. However, if the debris is caught, then no fire results and the fix is to remove debris and repair front end damage if necessary. (The “catching” modification could lower above a certain speed to allow normal clearance at slow speed.)

Putting steel armor under the battery would create an extra step in the battery swapping process, unless it remained with the battery during the swap. What does make sense is for Tesla Motors to consider all solutions and test them on test vehicles at their factory test track.

In the meantime, current owners should be prepared to pull over and evacuate the vehicle if road debris causes damage. Warnings appear on the screen and inform the driver properly. That part of the safety built into Model S is working perfectly. Knowing what can occur provides valuable time to save lives and contents. I plan to remove frunk items first and rear hatch items last if necessary. Obtaining a rental vehicle during a trip can occur with any make of car that fails. There is only one planned purchase for a cross country adventure outside of cell phone coverage. A DeLorme inReach SE Satellite Communicator to inform authorities of the vehicle location if stranded. I already stow a sleeping bag during winter weather. These items would help when driving ANY vehicle.

5

+17

Jason.Meador Says

Nov 15th, 2013 (6:43 am)

Three thoughts spring to mind:

1) I am glad that no one has been hurt in these fires. I think that speaks to some aspect of Tesla’s design. Those really are safe cars.

2) This seems like the down side of the trade-off in using the higher density batteries. I believe the Leaf has twice as many aggregate electric miles as the Model S (maybe 3 times as many) without any battery fires.

3) The “No recall, no way” seems to be the first large marketing mis-step for Tesla. I am sure Musk meant it as “Our cars are safe, no re-design needed” but it feels more company-serving rather than customer-serving. In the past, on things like the transmission, Tesla said “We will do what’s right for the customer, even if it costs us dough”. That should have been their response here.

Either way, if there’s a problem, it’s going to show up. Tesla is shipping enough cars now that the aggregate annual mileage will force the flaws to surface. Hopefully no one gets hurt in the process and hopefully Tesla will step up if there is a problem.

6

+11

Loboc Says

Nov 15th, 2013 (6:53 am)

A car cannot be designed in a public forum or by committee. IF there is a design flaw (I don’t believe there is) “S” can be retro-fitted like other cars.

But, only after simulation and design by real engineers. Sticking a steel plate out front may actually create a cleaver in an accident. What is the effect on crumple zones?

Didn’t we go through this kind of non-issue with Volt? Who was hurt when the government set a Volt on fire accidentally and then couldn’t reproduce the results? GM duly noted that there could be some beefing up for this exact scenario, but, when has this happened in the real world? Never.

All of this buzz around the Tesla ‘problem’ is just that: Buzz. The ‘problem’ (if one exists) is not even defined.

7

+1

Mark Z Says

Nov 15th, 2013 (7:19 am)

One interesting side comment about the fire situation was discussing it with friends. Did it affect their opinion of Model S? Not much. They all gladly let me drive them electrically to the AFI FEST in Hollywood last Saturday. Model S has become the car pool vehicle of choice to save fuel. They love Model S and enjoyed seeing the stars. http://www.youtube.com/watch?v=z4JF8pr2P7c

Mark Z: Model S has become the car pool vehicle of choice to save fuel.

My friends are funny when we car pool in the Volt. They all offer 25 cents to pay their share of the fuel costs. Jokers…

9

+4

MotoEV Says

Nov 15th, 2013 (7:47 am)

James McQuaid: This speaks louder than anything they might have said. Musk’s personality, which has driven this company to success, may also turn out to be its downfall.

‘It’s downfall’ LOL A bit dramatic (ala Shakespeare) at this time of the morning…

I don’t know Elon Musk personally. I own stock in Elon’s company. But certainly he’s no Macbeth or Julius Caesar. ‘Now bid me run , and i will strive with things impossible’

Tesla not providing an immediate response is not an admission of a problem but a methodical approach of determining the potential cause and providing a corrective measure. To go to the public and make statements without having facts is corporate suicide for any company. Now that Tesla has two similar road hazard events to investigate and examine, they will provide a corrective measure.

James McQuaid: Musk’s personality, which has driven this company to success

If Lutz’ personality did not bring down GM, then certainly Tesla will be ok with Mr. Musk supporting and protecting the Tesla brand and the company he owns.

10

+1

Nelson Says

Nov 15th, 2013 (8:02 am)

I don’t know what the inner make-up of their existing battery skate board is but one would think the bottom most inner layer would consist of a 1 inch thick polystyrene material with venting holes. Simple, light, insulative and protective.

kdawg: My friends are funny when we car pool in the Volt. They all offer 25 cents to pay their share of the fuel costs. Jokers…

I did appreciate one of my passengers paying the $13 parking cost. Two validations did not lower the maximum cost due to staying longer to dine and view the Thor movie. No one ever chips in for kWh. Maybe they think that Elon pays for all the charging!

12

+1

MotoEV Says

Nov 15th, 2013 (8:11 am)

These Tesla events do make one stop and consider how much one’s insurance premium is impacted by having such an expensive component (batteries) subjected to damage via a road hazard or accident. Gonna have to look into how the EV manufacturers try to minimize battery damage in an accident.

I could see under some circumstances how a non EV $2000 accident can turn into a $5000 EV accident.

Not unlike Ferrari, a damaged Tesla would have to be repaired by a specialized qualified technician and am not sure how that would work given Tesla is a newish and small company with few service centers.

Maybe Mark Z can clarify?

13

+2

Dave G Says

Nov 15th, 2013 (8:14 am)

Tesla CEO Elon Musk said there “definitely” won’t be a recall of the Model S. His track record shows he’s usually right about these kinds of things.

In other words, he probably knows a lot about what the National Highway Transportation Safety Administration is thinking, and is pretty sure they won’t require a recall.

And since Tesla has already completed their internal investigation of the third fire, Musk is saying there won’t be a voluntary recall.

And I agree with all this. The media today has a way of distorting reality. It’s not so much news. It’s what gets an emotional reaction. There’s an old movie from the 80’s called “Broadcast News” with William Hurt and Holly Hunter. This details the downfall of the modern media.

Engineering decisions should be based on facts, not emotions. For the Model S, the facts are:
1) Fires still occur less frequently than a regular gas engine car.
2) The fires all took several minutes to start, and grew slowly. It’s not like they exploded into flames.
3) None of the 3 fires spread to the passenger compartment.
4) No one was injured as a result of these fires.

In other words, people are talking about solutions to a problem that doesn’t exist. This is the type of thinking that leads to over-designed, less competitive products.

I’m sure everyone is getting sick of my chart, so I won’t show it here, but the point is that EREVs and commuter BEVs can replace 90% of gasoline use, so in my mind, long-range BEVs like the Model S are already over-designed. Why would we want to over-over-design it?

Best reply so far. Tesla should not try to brush the incident under the rug, but show they are investigating on their own.

I think the “cow catcher” idea is totally impracticable and would do more harm than good.
Steel plate sounds reasonable.

Since the Model S has an adjustable height suspension, and it is designed to automatically lower at highway speeds, I suggest that the first thing Tesla should do is issue instructions or a software patch that allows concerned drivers to defeat the lowering and minimize chances of this sort of impact.

In future maybe radar could identify road debris and raise the car automatically.

15

+7

taser54 Says

Nov 15th, 2013 (8:26 am)

Why must the retrofitted “armor” be steel? Make it a composite like Tegris, a self-reinforced polypropylene (PP) composite. It’s used for the aero splitters for Nascar. It is also being used as ballistic shielding for crew pods in military vehicles.

The Tesla S is a great car and I would love to own one, even in todays configuration. But given the two fire incidents stemming from road debris, I think that Tesla/Elon should make a change. Perhaps it would simply be reducing the amount the S is lowered at highway speeds.
I have read that the ground clearance goes down to 4.46″ at highway speeds but the forum entry below says it is actually 5.21″ at highway speed. 5.21 isn’t bad, 4.46 is a bit low for safety but great for aerodynamics. There are sports cars out there with 4.6″ of clearance (M5) but they don’t have a barn door sized point of failure like an Tesla S does.
If the S clearance is actually 4.46″ at speeds over 60 mph, that may need to be adjusted up.
The aluminum (wasn’t it supposed to be steel when Elon was talking about it in 2011?) battery pack cover plate may need to be beefed up as well. If it is replaced with a slightly thinner but heavier and stronger steel plate, part of the ground clearance issue would be addressed but it would probably weigh a noticeable amount more than an aluminum battery pack cover plate.
And when this is discussed, are there two plates being talked about? The forward steel skid plate that is around 5′ wide but less than a foot long, and then the battery pack cover plate, which is usually referred to as being made of aluminum?
Regardless, with or without the two improvements above, the Tesla S is a great car. It could be even better/safer, but that probably isn’t necessary for any reason other than public relations.

Musk and others have focused on the energy stored in the battery relative to energy stored in a tank of liquid dino fuel. The speed with which that energy can be released is at least as important and probably tilts the safety argument in favor of liquid dino fuel.

KNS

18

+1

Dave G Says

Nov 15th, 2013 (9:00 am)

MotoEV: These Tesla events do make one stop and consider how much one’s insurance premium is impacted by having such an expensive component (batteries) subjected to damage via a road hazard or accident.

As I’ve said before, in all 3 cases, these accidents would probably have totaled a regular car.

In any case, insurance companies use actual statistics to determine rates, not media hype.

19

+7

Dave G Says

Nov 15th, 2013 (9:06 am)

KNS: Musk and others have focused on the energy stored in the battery relative to energy stored in a tank of liquid dino fuel. The speed with which that energy can be released is at least as important and probably tilts the safety argument in favor of liquid dino fuel.

First, 98% of the oil that we pump out of the ground came from ancient algae. Fossil fuels have nothing to do with dinosaurs. Another piece of media fiction.

Second, all of the Tesla fires took several minutes to start, spread slowly, and never reached the passenger compartment. So it’s actually the other way around. The speed with which the energy is released in an accident tilts the safety argument in favor of batteries.

“A steel sheet the same square area as a quarter-inch-thick aluminum sheet would be only one-twelfth of an inch thick to weigh the same. However, steel’s tensile strength and puncture resistance can be so high, it might not take much – and this also shows the present aluminum “armor” under a Model S is only equal to one-twelfth of an inch, or .083-inch-thick steel.”

I think this would also be cheaper. Aluminum can be expensive. Of course if money is no object, it would be cool to make it stainless steel. No worries about rust and it could really shine.

Dave G: And since Tesla has already completed their internal investigation of the third fire, Musk is saying there won’t be a voluntary recall.

But I wonder if there will be a design change for the next gen Model S? And/or if the Gen3 “Bluestar” will use an aluminum plate?

Whether a recall happens or not, this is obviously an area for improvement, and all companies should continuously improve their products. If it costs less, weighs less, and does a better job, why not just switch to a steel plate?

22

+2

Dave G Says

Nov 15th, 2013 (9:39 am)

kdawg: But I wonder if there will be a design change for the next gen Model S? And/or if the Gen3 “Bluestar” will use an aluminum plate?

Good point. I’m sure Tesla is looking at different possibilities for improving the next design. Anything can be improved.

23

+5

Schmeltz Says

Nov 15th, 2013 (9:41 am)

I don’t think this problem will go away completely until something gets revised to the floor of the vehicle to stop these fires from happening. Musk and Tesla should make good on their claims that the Tesla is super safe, and engineer a solution—sooner rather than later. And I would do a recall too as an act of good faith.

I wonder if anyone has considered Kevlar? Lighter than steel but expensive. Just a thought.

So it’s not really “armor” since it’s aluminum. Looks like they’ll have to double it or add a thin layer of steel as a worst case. Maybe raise the ride height somehow. All overkill, just like the Volt battery enhancement bracket…

MrEnergyCzar

26

+3

Dave G Says

Nov 15th, 2013 (9:56 am)

kdawg: Of course if money is no object, it would be cool to make it stainless steel. No worries about rust and it could really shine.

If money were no object, it would be carbon fiber. Stronger than steel, and no worries about rust.

27

+3

Dave G Says

Nov 15th, 2013 (9:59 am)

MrEnergyCzar: All overkill, just like the Volt battery enhancement bracket…

Exactly, +1

28

+7

bobchr Says

Nov 15th, 2013 (10:00 am)

Arrogance and a bad haircut is no way to go through life son. Elon might have said, we are fully cooperating with the NHSTA, as we have more complete information we will convey it to you. Prognosticating what a regulatory department may do or conclude is not a message he needs to send. It betrays a holier than thou and I know what is better for you attitude.

Please share with us what company you have created. Anything close to SpaceX or Tesla?
Your insight must be based on your years of experience as an executive in a company (sarcasm)
What does his haircut have to do with anything substantive?

Definition of arrogance: Take a look in the mirror!!!!

30

+2

steve Says

Nov 15th, 2013 (10:15 am)

Still the good news is nobody was hurt, just the car burned up. I think it’s still a problem. After a “safe” fire were these cars repairable or a total loss?

It apparently takes time after impact for a problem to become apparent. 30-45 minutes in these cases?

How’s this for a scenario:

Driver hits something 5-10 minutes from home. Parks in his attached garage doesn’t notice anything. Next thing he knows his house is on fire. The ICE car likely wouldn’t have made it home to smolder and cause problems later.

31

+5

Steverino Says

Nov 15th, 2013 (10:29 am)

The Volt’s ground effects come from the flexible air that sometimes scrapes the ground. The Tesla’s ground effects come from lowering the car. The more you lower a car to the ground, the more likely it is that it will contact road debris as demonstrated by the two Tesla drivers.

I was paraphrasing a line from the movie Fast times at Ridgemont High. I was merely pointing out that Mr Musk could have phrased things differently because even though all the data is not in Tesla as a company is still in it’s infancy and does not need bad PR or a vendetta by media hounds. Neither Space-X or Tesla are unqualified successes at the moment they are still in their infancy. GM reacted to a series of mistakes made by the NHSTA and really did not need to, in doing so they built good will in general although some talking heads still misrepresent the facts to further their own agenda. Remember when Apple released the iPhone 4 with the antenna susceptible to the signal death grip. Even though Jobs demonstrated that any smart phone on the market had a so called death grip Apple was still vilified by the pundits and media types and for releasing a clearly superior but still somewhat shoddy product. So much so that even Consumer Reports even though they acknowledged that it was a superior product could not recommend it. I may not have had Mr Musk’s level of success but in my experience in the business world I have been coached by my bosses how to present information to superiors and the masses. But for the grace of luck has Mr Musk succeeded so far history in the automotive word has had many failures, Tucker in the 40’s and more recently Fisker. I thought my advice on Mr Musk was sound but it is your right to disagree. All I know is Tesla stock has dropped 34% since it’s all time high. Tough talk and arrogance did not work with Chrysler and their Jeep product. Just saying.

35

+3

bobchr Says

Nov 15th, 2013 (11:06 am)

By the way, everyone keeps pointing out no one was hurt. IS the proper course of action to wait until some one is or be more proactive?

36

+6

Neromanceres Says

Nov 15th, 2013 (11:06 am)

Simply this will come down to what is considered a normal event.

If the Model S battery compartment cannot contain what would be considered typical road debris then I believe Tesla has an issue that needs to be addressed. If the road debris in these incidents are atypical then move along nothing to see here.

I would imagine that testing could be done to simulate a typical road debris event and the shield should be designed to handle that.

If it turns out a new shield design is to be used a high strength steel alloy will likely be the most cost effective solution.

Tesla needs to tread carefully here. Incidents like this could easily snow ball in such a way that could easily bring the company down. I’m not saying Tesla has a problem but Tesla needs to show to be open and cooperative or it will look like they have something to hide.

37

+1

Jackson Says

Nov 15th, 2013 (11:17 am)

There are thin, lightweight coatings which can be applied to any surface to increase resistance to penetration. They even make ‘bullet proof’ wallpaper:

1) If nothing is changed about the Model S, then these fires caused by hitting road debris will continue to happen at the current rate. Common sense?

2) If I’m not mistaken, there are 150,000 fires with gasoline cars per year in the U.S. Dividing by 250M cars in the US gives… 150K / 250M = 0.0006 fires per car per year.

Now, let’s multiply 0.006 by the average number of Model S cars we’ve had on the roads in 2013, which is about 10,000, and we get… 0.0006 * 10K = 6. If the Model S was having fires at the same rate as gasoline cars, then there would have been 6 fires this year.

The Model S is doing better at avoiding fires than gasoline cars.

3) I vote for increasing the ride height of the Model S to decrease the likelyhood of fires resulting from hitting road debris. My subcompact SUV has a ground clearance of 8 inches, and it doesn’t cause any stability problems when travelling at 75 MPH.

No low riding electric car for me. I’ll wait for the AWD electric car with good ground clearance.

Isn’t it liquid cooled? To me you would want the battery insulated from the environment so you could better control its temperature.

42

+2

Noel Park Says

Nov 15th, 2013 (11:31 am)

Mark Z: Putting steel armor under the battery would create an extra step in the battery swapping process, unless it remained with the battery during the swap. What does make sense is for Tesla Motors to consider all solutions and test them on test vehicles at their factory test track.

#4

How about ejection seats? It’s not a new concept. Jonathan Winters first proposed them in “Elwood P. Suggins and His Automobile” many years ago. Of course his goal was to get rid of backseat drivers, but the concept would seem to fit here as well.

Where else do you go from “up” (or, in the case of Tesla, “most high exalted”)? I’ve been waiting for some shoe to drop ever since that magic week or two that the “S” was declared from all rooftops to be the greatest thing since sliced bread.

Another way to do the math is by miles traveled and this is how Elon replied.http://www.teslamotors.com/blog/model-s-fire“The nationwide driving statistics make this very clear: there are 150,000 car fires per year according to the National Fire Protection Association, and Americans drive about 3 trillion miles per year according to the Department of Transportation. That equates to 1 vehicle fire for every 20 million miles driven, compared to 1 fire in over 100 million miles for Tesla. This means you are 5 times more likely to experience a fire in a conventional gasoline car than a Tesla!”

Dave86: I vote for increasing the ride height of the Model S to decrease the likelyhood of fires resulting from hitting road debris. My subcompact SUV has a ground clearance of 8 inches, and it doesn’t cause any stability problems when travelling at 75 MPH.

… except that the low stance adds a great boost to aerodynamic efficiency, which is of great importance for overall EV design.

46

+5

Zeede Says

Nov 15th, 2013 (11:39 am)

Honestly, hitting a trailer hitch is going to penetrate almost any reasonable “plate armor”, although it would be interesting to see some computer modeling of that impact and see how much less damage there would’ve been with a 1/8th inch steel plate instead.

bobchr: It betrays a holier than thou and I know what is better for you attitude.

#28

No s**t. +1

“Pride goeth before destruction, and an haughty spirit before a fall.”

48

+5

hvacman Says

Nov 15th, 2013 (11:44 am)

Loboc:
A car cannot be designed in a public forum or by committee….
But, only after simulation and design by real engineers.

+1

It appears there is a problem and I suspect that a bunch of S’s are intentionally hitting “debris” at Tesla’s test/research facilities even as we speak. Like GM’s procedure in responding to the initial NHSTA’s Volt post-collision battery fire event, the first step to solution that engineers employ is to define the problem. That means going to the lab and testing to see if they can re-create the “anomaly”, which then leads to understanding the root causes. Only then can they explore appropriate mitigations (if any). In the Volt’s case, the selected solutions involved additional lateral steel reinforcement around the battery and additional emphasis, development, and advertising of standard protocols regarding proper EV post-accident battery discharging/coolant draining procedures.

This was the procedure for the Challenger (failed solid booster O-rings at low temperatures), the Tacoma Narrows bridge failure, and countless other engineering failures. There is a fascinating book called “Why Buildings Fall Down” which reviews through history various famous structural failures, the investigations into the failures, and the lessons learned.

Debate and hypothesize as much as you want – Tesla will follow SOP on these fires and respond as a responsible technology company does, ignoring comments from the peanut gallery (i.e. – us). I am very curious about what that response will be.

That particular jerk owns a golf resort in my little city, so I’ve gotten a front row seat to see a true PITA in action.

50

+2

Jackson Says

Nov 15th, 2013 (11:49 am)

“… the 5-foot-wide, 9-foot-long underside is tantamount to the proverbial barn door.”

And it’s this aspect of a large, underfloor pack which answers the question “Should Tesla upgrade its battery ‘armor’”: Yes.

I wouldn’t be too surprised if some beefing up isn’t eventually required to be done for any sub-floor pack.

Achilles’ heel? More like his whole lower half. 😉

51

Noel Park Says

Nov 15th, 2013 (11:50 am)

bobchr: But for the grace of luck has Mr Musk succeeded so far history in the automotive word has had many failures, Tucker in the 40′s and more recently Fisker.

#34

Wait for it…………………………… +1

52

gsned57 Says

Nov 15th, 2013 (12:07 pm)

If there is a camera on the front of the car couldn’t it look for road debris and raise the body a few inches quickly if needed. Cars have a million difference sensors so what’s one more? I guess the question is response time and if you can increase the ride height that quickly.

Sorry my question was rhetorical. Tesla has 3 liquid cooling loops; drive-train, cabin, and batteries. I wouldn’t buy an EV that wasn’t liquid cooled/heated using today’s battery chemistry. If they come up w/better battery chemistry, that can tolerate extreme temps, then I’ll look at air cooled and resistive heating.

Zeede: it would be interesting to see some computer modeling of that impact and see how much less damage there would’ve been with a 1/8th inch steel plate instead

Screw computers. Let’s do it Mythbusters style and break some stuff

59

+1

DonC Says

Nov 15th, 2013 (12:48 pm)

Since Tesla doesn’t seem interested in investigating the root cause of the problem isn’t known, which means the solution can’t be known.

CaptJackSparrow: The Volt’s in on the floor as well, just not as large of a footprint.
So, *If* it got hit with the same road junk, would the LiMn have the same chemical reaction

Very good point. I always thought the Leaf just had its batteries under the back seat until George pointed out there are also some under the front. But they’re under the front seat and not towards the front of the car. I don’t think any other car spreads out the batteries like the Model S.

Also, there is the question of shielding. The Volt’s batteries have a lot more shielding. I’ve heard three wraps as opposed to one on the Model S. Then there’s the chemistry, as you’ve pointed out. The Model S batteries are a variant of Li-cobalt, which are less stable than other chemistries. Finally there are the connections. It could be that the thousands of connections needed to wire the small cells together are part of the problem. Many possibilities.

60

+2

Mark Z Says

Nov 15th, 2013 (12:48 pm)

gsned57,
Unfortunately, when the driver manually raises Model S for a driveway or other obstruction, it takes at least 5 seconds. The rear rises first, then the front of the car. The high and very high settings are only available when stopped or driving slowly.

gsned57: I guess the question is response time and if you can increase the ride height that quickly.

You’d probably end up w/something like a lowrider bounce 😀

62

+2

DonC Says

Nov 15th, 2013 (12:50 pm)

kdawg: My friends are funny when we car pool in the Volt.They all offer 25 cents to pay their share of the fuel costs.Jokers…

I took my wife to the airport. When I picked her up I had to make two trips because her flight was diverted due to fog. My joke was that her reimbursement for the three round trips would cover the cost of running her car for the year (accurate actually). LOL

DonC: I don’t think any other car spreads out the batteries like the Model S.

Here’s how the “floor” battery cars look. There’s probably others. However it should be noted that Ford, GM, and Volvo seem to locate their batteries in safer locations/configurations. (I still like them in the floor better though)

The battery is not just liquid cooled, unless it has zero thermal transfer through its shell. Since I suspect that is not the case, I would imagine the choice of Aluminum was not just a weight consideration.

NPNS!
Volt#671

66

CaptJackSparrow Says

Nov 15th, 2013 (1:20 pm)

I have just fixed the Model S battery fire problem!!!

67

CaptJackSparrow Says

Nov 15th, 2013 (1:20 pm)

Like to hear it?

68

CaptJackSparrow Says

Nov 15th, 2013 (1:21 pm)

Here it goes!

69

+1

CaptJackSparrow Says

Nov 15th, 2013 (1:21 pm)

Just like what our data center has, install a small 1/2 gallon canister of Halon and trigger it in the batt pack upon penetration (or fire) detection.

Thank you, Tesla will receive my bill for the cost of 2 Model X’s and one Model E.

CaptJackSparrow: The Volt’s in on the floor as well, just not as large of a footprint.
So, *If* it got hit with the same road junk, would the LiMn have the same chemical reaction?

No Lithium Manganese would not have the same reaction. Lithium Manganese reacts slower with the air. So it would dissipate the same energy over a longer period of time reducing the fire potential. My understanding is that the energy Lithium Cobalt releases in seconds would be released in hours with Lithium Manganese.

72

+2

bobchr Says

Nov 15th, 2013 (1:47 pm)

CaptJackSparrow:
Just like what our data center has, install a small 1/2 gallon canister of Halon and trigger it in the batt pack upon penetration (or fire) detection.

Thank you, Tesla will receive my bill for the cost of 2 Model X’s and one Model E.

Good luck trying to collect, you might want to forward the suggestion to E.Musk@Tesla.com. In order for the Halon to be effective the car cannot be moving an must displace the air completely in an enclosed airtight space for at least 10 minutes. If you have a structural rupture in the battery area the effectiveness of the Halon gas might be compromised. As a former member of the NFPA and and having taken a seminar on NFPA 72 (Fire alarm and Signaling codes) and NFPA13 (sprinkler design) the issue may have been introduced to me a couple of times.

I dunno, the thought of my head bouncing off of the roof is giving me a headache as we speak, LOL.

+1 anyway, because I don’t see it meriting a -1

I think it would push you into the seat not hit your head on the ceiling.

74

+3

George S. Bower Says

Nov 15th, 2013 (1:59 pm)

CaptJackSparrow: The Volt’s in on the floor as well, just not as large of a footprint.
So, *If* it got hit with the same road junk, would the LiMn have the same chemical reaction?

Here are the combustion rates. They are in degrees C per minute. So it is how fast the fire gets hot right after ignition. Model S chemistry is almost a factor of 100 faster than our Volt.

Charles Whalen:

“LiMn2O4 [Nissan LEAF / GM Volt] reaches a peak combustion rate of 2.5C/min, while LiFePO4 reaches a peak combustion rate of 3.4C/min. Contrast those to the combustion rates of the batteries that Tesla uses — in the Roadster, LiCoO2 reaches a peak combustion rate of 360C/min, and in the Model S, LiNi.8Co.15Al.05O2 reaches a peak combustion rate of 280C/min…”

75

+1

BAZINGA Says

Nov 15th, 2013 (2:02 pm)

I’m not an expert but I did stay at a Holiday Inn Express once, but given the loaction of the Tesla’s battery pack, one has to wonder why auto manufactures don’t position their fuel tank in a similar location/configuration? Safety????

76

+2

George S. Bower Says

Nov 15th, 2013 (2:03 pm)

CaptJackSparrow:
Just like what our data center has, install a small 1/2 gallon canister of Halon and trigger it in the batt pack upon penetration (or fire) detection.

Thank you, Tesla will receive my bill for the cost of 2 Model X’s and one Model E.

They already have a version of that. It is a gel that solidifies when it gets hot. So this gel keeps adjacent compartments from catching fire. The Gel and the compartmentalization probably kept the fire from spreading under the passenger compartment.

Also I believe the front of the pack is desined to “Vent forward” in case of fire.

77

+3

DonC Says

Nov 15th, 2013 (2:13 pm)

kdawg: Here’s how the “floor” battery cars look.There’s probably others.However it should be noted that Ford, GM, and Volvo seem to locate their batteries in safer locations/configurations.(I still like them in the floor better though)

Some of these aren’t on the road in any number (if at all) and in most cases the placement is further away from the front.

George S. Bower: Charles Whalen:
“LiMn2O4 [Nissan LEAF / GM Volt] reaches a peak combustion rate of 2.5C/min, while LiFePO4 reaches a peak combustion rate of 3.4C/min. Contrast those to the combustion rates of the batteries that Tesla uses — in the Roadster, LiCoO2 reaches a peak combustion rate of 360C/min, and in the Model S, LiNi.8Co.15Al.05O2 reaches a peak combustion rate of 280C/min…”

Really great information George. Very nice to be able to quantify the difference.

78

+2

MotoEV Says

Nov 15th, 2013 (2:31 pm)

I never gave this serious thought until reading through the posts today but how did Tesla ‘shortcut’ the development cycle with the Tesla products when GM, Nissan, Toyota, BMW and others have spent over a decade in the Hybrid, EV, PHEV space?

Not assessing cause/blame but there is much to be said from obtaining learnings from gaining practical knowledge over time. In many cases, this is how mistakes/ problems are identified and corrections are applied in the design process.

CaptJackSparrow: Just like what our data center has, install a small 1/2 gallon canister of Halon and trigger it in the batt pack upon penetration (or fire) detection.

They already have something like this. The Model S battery pack has a gel-like fire retardant which expands and solidifies in extreme heat, preventing fire from spreading to the entire pack.

EDIT: You beat me to it at #76 George. I must have been distracted 😉

80

+2

RonK Says

Nov 15th, 2013 (2:40 pm)

I think there are really two choices here.

1. First we can decide that the incidence of severe road debris damage is a rare enough event that redesign is not necessary (like having to redesign a car to handle the weight of a 100 year oak tree that may fall on it.) Recent data, however, suggest (for many of the reasons listed above) this is unlikely because of very tight road clearance, very high Li-ion battery energy density, and susceptibility to internal shorting and heat generation if the battery cells are damaged.

2. Or we can decide to evaluate redesign options that reduce the probability of such damage occurring. Practical, cost effective solutions can be developed by engineers with CAD and CAE simulation packages, so the reliability of the fix can be very high, and the impact on vehicle performance and weight would be calculated, not guessed. One countermeasure that has a good chance of improving the underbody protection from such concentrated loads is an advanced high strength steel sheet of over 1000 MPa tensile strength (several time the strength of any aluminum automotive sheet). It’s no accident that the Volt engineers chose to use for the Volt skid plate, no matter what the role of NHTSA was in that episode. New steel grades have already transformed the passenger compartment of modern steel cars and trucks into safety cages. For example, they help fend off high impact loads and minimize penetration into the passenger space like in the IIHS side impact test. While we haven’t actually done a simulation solution for an “underbody crash”, we do have the technology to do just that.

DonC: Some of these aren’t on the road in any number (if at all) and in most cases the placement is further away from the front.

But the designs were approved by an engineering team at some point, and they all had to be crash tested.

Makes me wonder if the NHTSA will go overboard on this and create a “road debris” test.

82

+3

CaptJackSparrow Says

Nov 15th, 2013 (2:49 pm)

OK, then how about this for the fix…

Don’t drive the Model S Drunk and avoid “Road Debris”?

😛

83

Streetlight Says

Nov 15th, 2013 (2:54 pm)

My GMC Sierra Classic has a transmission guard. GM’s has made these from day one for their trucks. Typically 4mm-5mm steel (of course). That’s what would have protected that MODEL S.

We knew Li-ion batteries raise fire risks many moons back. First laptops. then EV’s, Boeing’s saga. Now TESLA. Don’t condemn LI-ion. As CEO Musk states gas too is even more flammable. He makes a rebuttable point. The old VW with its front fuel tank was always at more risk. A co-worker way back was seriously injured c.1967 in his VW in a front-end collision. I could not post how he feels about VW and its front fuel tank.

What needs to be done and I realize this is an on-going issue in our national labs, is setting a testing standard for Li-ion defense against being compromised.

OT: GM stock is at $38.91/share and was over $39 at some point today. It may close higher that it has since the stock was re-issued.

85

+4

BAZINGA Says

Nov 15th, 2013 (3:16 pm)

And this just in:

“GM also is recalling nearly 15,000 Malibus in North America from the 2013 model year because wiring beneath the seats can catch fire.

The company says wires in cars with eight-way power front seats can rub against the seat frames. This can wear away the insulation and cause a short circuit that can cause sparking or a fire. The problem also can make the seats move unintentionally, and cause melted wires and smoke, GM said.

GM says dealers will inspect the seat wiring and repair it if needed”

The key “The company says it’s aware of two unattended fires that went out on their own. It knows of no crashes or injuries”.

And GM issued a RECALL for that. Interesting how GM and Tesla handle these situations. One is the Golden Boy and the other Gevernment Motors……

86

Noel Park Says

Nov 15th, 2013 (3:45 pm)

bobchr: I totally forgot about Delorean, Bricklin and probably a bunch of others. Not to mention car boat and flying car inventors that never got off the ground.

</blockquote
#63

Exactly. +1

Not to mention Studebaker, Packard, Kaiser/Fraser, American Motors, Pontiac, Oldsmobile, De Soto, Plymouth, Edsel, Ls Salle, Deusenberg, Mercer, Stutz, Crosley, Powell, and even the poor old Muntz Jet. And that's just the beginning. I would bet that through the history of the U.S. car business the total must be t least 100.

I'm always remained of the words of Tommy Lasorda to a second guessing sports writer:

"This f****n' job ain't that f****n' easy!"

87

MotoEV Says

Nov 15th, 2013 (3:54 pm)

I hear what you are suggesting but there MAY be some merit to the thought that Tesla (being a small company) would not have the testing facilities and resources to test as thoroughly as the much larger manufacturers. For example Mercedes spent tons on hours over a long horizon to test the new S-Classe in severe conditions. This is one of the benefits the larger companies have over the smaller ones.

RonK: First we can decide that the incidence of severe road debris damage is a rare enough event that redesign is not necessary (like having to redesign a car to handle the weight of a 100 year oak tree that may fall on it.)

88

MotoEV Says

Nov 15th, 2013 (3:58 pm)

CaptJackSparrow: OK, then how about this for the fix…
Don’t drive the Model S Drunk and avoid “Road Debris”?

If you have ever ran over something on the road at 70 MPH and you hear that ‘pow and wallop’ you never forget it and you dread getting out of the car to assess the damage.

89

+1

Skotty Says

Nov 15th, 2013 (3:58 pm)

A few notes —

1) There is some steel in the Model S. Steel was added to the sides (I think in the vertical structure between the doors) to provide the desired level of crash safety.

2) We don’t really know what the structure is beneath the battery. I’ve heard it’s just an aluminum plate. I’ve also heard it’s an aluminum plate with a steel frame above it. There are a lot of options to strengthen the underside plating if they want to, which may or may not include a change in the metals/materials.

3) Tesla is closely looking at the incidents, though they may choose not to share much with the public. If they decide they want to protect it better but the existing design is not unsafe, something I consider a likely scenario, then there will likely be an unpublicized design change to improve battery protection, but no recall on existing cars. Even if the design can be better, they don’t want to perform a very costly recall when the existing design is considered sufficient.

90

+1

Noel Park Says

Nov 15th, 2013 (3:59 pm)

George S. Bower: I think it would push you into the seat not hit your head on the ceiling.

#73

It pushes you into your seat until it tops out and suddenly stops rising. Then your body tends to keep going up unless/until the seat belt stops you or your head hits the roof. And I am living proof of how far set belts can stretch in a hard impact.

Benz or some such has a system that automatically tightens the belts when it detects a crash. So maybe they could incorporate that. One more layer of complication, LOL.

Keep It Simple Stupid!

91

Jonathan Baker Says

Nov 15th, 2013 (4:11 pm)

Nelson:
I don’t know what the inner make-up of their existing battery skate board is but one would think the bottom most inner layer would consist of a 1 inch thick polystyrene material with venting holes.Simple, light, insulative and protective.

I’m not sure that 1 inch thick polystyrene would be of much use in adding protection. It actually is considered flammable, will support burning and has little ability to inhibit puncturing.

I think that the use of a Kevlar shield in conjunction with the current aluminum plate would create a significant puncture barrier without appreciable added weight. How to add the Kevlar would be an engineering effort.

I am not convinced that these two incidents are significant evidence of a design deficiency, however. Any statisticians out there who want to comment?

It pushes you into your seat until it tops out and suddenly stops rising.

Wear your seat belt

96

+1

James Says

Nov 15th, 2013 (4:55 pm)

Mark Z,
Comment #4. Well said, and I totally agree. You have a balanced way of looking at the situation
IMO.

Look – I believe it is the best car in the world. It’s not perfect. Yet I believe it’s not
“dangerous” – and I’ll stick to that until proven otherwise.

The fact the car lowers itself was a big plus for me, as I suggested GM do this with Volt – it really adds to efficiency on the hwy I will admit that I did not consider road debris, yet I’m positive Tesla’s engineers did. They believed their safety checks and balances were adequate.

I keep wondering if Kevlar may be the answer, or simply issuing a software update to
disengage the suspension-lowering feature. I lowered my 2nd gen Prius 5/8″ and saw a dramatic result in hwy mileage with no road debris puncturing incidents in 3 years. I do hit curb cuts diagonally when possible and have rubbed the bottom even when the Prius was stock height. My Volt has yet to bottom out even on some tricky angled road-to-entryway transitions.

CHARGE! ,

James

97

Nelson Says

Nov 15th, 2013 (4:56 pm)

Jonathan Baker: I’m not sure that 1 inch thick polystyrene would be of much use in adding protection. It actually is considered flammable, will support burning and has little ability to inhibit puncturing.

That’s strange; I’ve seen ads for fireproof boards.http://www.alibaba.com/showroom/fireproof-foam-board.html
I’m sure they’ll melt at high temps but they may slow the spread of fire. I agree they won’t be much help preventing pointed objects puncturing the shell but they should help with blunt object damage.

My dad used to say, “It’s not the fall that kills you, it’s the sudden stop”.

101

+1

Jackson Says

Nov 15th, 2013 (5:42 pm)

Forget about raising the car. Use a sensor to deploy the ‘cow-catcher’ (which would likely be a hazard itself if simply mounted undercar full-time). A debris deflector would have far less mass than the whole car, and could be designed to respond very quickly. A spring-loaded bar, for example, could be deployed almost instantly by a solenoid release, then wound back more slowly with a screw-drive mechanism. Not KISS, but …

102

+2

Jonathan Baker Says

Nov 15th, 2013 (6:04 pm)

Nelson: That’s strange; I’ve seen ads for fireproof boards.http://www.alibaba.com/showroom/fireproof-foam-board.html
I’m sure they’ll melt at high temps but they may slow the spread of fire.I agree they won’t be much help preventing pointed objects puncturing the shell but they should help with blunt object damage.

NPNS!
Volt#671

My previous comment pertained to polystyrene. I’m not sure what material is being supplied by your reference. Maybe it is possible to make polystyrene inflammable – I’m no materials expert for sure!

I’m willing to bet that Tesla engineers are working up proposals to add strength to the underbody. Whether any will be implemented remains to be seen. As I said before, I’m not sure if two fires caused by road debris are statistically significant. In order to fully understand the possibility of a problem, one would have to know how many other instances of road debris impacting the underside without penetration have occurred, that being one of several considerations in the equation.

Bottom line for me is: can I afford a Model S? The answer is no, and that saddens my geeky soul 8^( If money were not a consideration, I would place an order for one in a New York minute after finishing this post! I wouldn’t give up my Volt, though!

103

steve Says

Nov 15th, 2013 (6:24 pm)

gsned57:
If there is a camera on the front of the car couldn’t it look for road debris and raise the body a few inches quickly if needed. Cars have a million difference sensors so what’s one more?I guess the question is response time and if you can increase the ride height that quickly.

Imaginative, clever, but not very realistic.

104

Zeede Says

Nov 15th, 2013 (7:03 pm)

So, part of the issue is that the chemistry used in Tesla’s batteries is FAR more volatile in terms of Celcius degrees per minute, and that it’s spread out to a 45 sq/ft surface area.

They’ll probably have to add a thin steel plate, similar to a skid plate or transmission shield. I think they’ll also start investigating less volatile battery chemistries.

105

Sean Says

Nov 15th, 2013 (7:11 pm)

Tesla needs to make there car safer after all do you think Tesla should use the incredibly rare metals when it comes to the best quality?

Or maybe Tesla could go by combining there metals as in metal alloy style maybe they could combined some of the strongest and lightest metals in the world for both the battery in a metal cage to protect it and the metal plate below the passengers that covers it.

only problem is that these metals are among some of the most expensive in the world so what kind of metals do you think Elon could combined so that he can prevent these fires from happening?

Also did you notice on the Tungsten link that it is the most heat resistant metal on earth of not melting until over 6,000 degrees Fahrenheit!

If he could use that metal I wonder if the battery fires could be prevented a whole lot better then now think about it!

Seriously I just don’t see the big deal here. We are not going to change the fact that debris is littered all over our roads. How many of us have run over sticks, rocks, tire pieces etc? It is a fact of life.
I use the look and avoid method. No modifications necessary!
But seriously (again) the media is all over this. I just don’t understand why anyone would be so opposed to this technology. Developed in America, Built in America by American workers. What is wrong with America now a days? Since when have we not embraced our new technolgies. Had we done this to the space program after the Apollo fire we would never have gotten to the moon.
As has been pointed out – everyone of the owners walked away from these fires. If they had involved volatile fluids such as gas and oil or diesel it might very well have been a different story. Fluids have a nasty habit once liberated to flow and splash all over everything. As Pinto and Crown Vic owners can attest. And as far as electrical fires in general go there have been many automotive electrical fires with ICE’s in them. Electrical fires are also a fact of life and happen. I was driving on the I90 last week a major highway thru New York state and there was a late model – non BEV – car burning like crazy. When I stopped at the rest area down the road I happened to see a state trooper who had responded to the accident. We talked about it not being a Tesla jokingly and he noticed I was driving a Volt. Complemented me on it and shared with me that the first responder fire department siad this car had expierenced an electrical short and burned to the ground. The driver was nearly overcome by smoke. Had it been a Tesla S the driver would have been warned, had time to pull over and not be overcome with smoke.
Did anyone here about this on teh news? Nope. I bet it didn’t even make the local news feed. It wasn’t in teh paper the next day and when I looked for it on teh web ….. surprise it wasn’t there. Not note worthy.
Anyway long live Tesla and full steam ahead.

Hmmmmmm Halon is an asphyxiant (sp?) and not approved for automotive use. (yet). Not sure I would like being in a confined space when it discharged. Yes I know you said battery compartment but……. who knows what happens in an accident and how the passenger compartment will be penetrated.
Anyway, it’s an idea. I still think a titanium shield or kevlar would do the job. However if any sports car hits a 3 ball trailer hitch at highway speeds its going to be ugly. I drive a Z06 as well as my Volt and I would not want to hit that with either car. Both could be substantially damaged and if the steering is affected I could loose control and end up in a very bad way.
Bottom line – Look and avoid, if not engineer as best as practicle to shield the battery and vitals

When I watched that video, and it got to the part of the car jumping the object in slow motion, I made the Six Million Dollar Man noise in my head.

109

rdunniii Says

Nov 16th, 2013 (1:14 am)

MotoEV: ‘It’s downfall’LOLA bit dramatic (ala Shakespeare) at this time of the morning…

I don’t know Elon Musk personally.I own stock in Elon’s company. But certainly he’s no Macbeth or Julius Caesar.‘Now bid me run , and i will strive with things impossible’

Tesla not providing an immediate response is not an admission of a problem but a methodical approach of determining the potential cause and providing a corrective measure. To go to the public and make statements without having facts is corporate suicide for any company. Now that Tesla has two similar road hazard events to investigate and examine, they will provide a corrective measure.

If Lutz’ personality did not bring down GM, then certainly Tesla will be ok with Mr. Musk supporting and protecting the Tesla brand and the company he owns.

I don’t recall Steve Jobs personality bringing down Apple either. You remember, the guy that dissed the people who held the phone wrong and covered the antenna nor the folks that had the battery problems with iPhones either.

110

Fred Says

Nov 16th, 2013 (1:42 am)

The chance of a fire in an ICE car is much less than Elon implies. Most car fires occur when fuel lines leak fuel on hot components. Only 4% of car fires result from a collision. If you factor that in, Tesla has a much higher rate of fires from collisions than an ICE.http://www.usfa.fema.gov/downloads/pdf/statistics/v13i11.pdf, page 6.
“Collisions, as a factor contributing to ignition, resulted in 4 percent of all highway vehicle fires”

111

+1

Koz Says

Nov 16th, 2013 (3:39 am)

Fred:
The chance of a fire in an ICE car is much less than Elon implies. Most car fires occur when fuel lines leak fuel on hot components. Only 4% of car fires result from a collision. If you factor that in, Tesla has a much higher rate of fires from collisions than an ICE.http://www.usfa.fema.gov/downloads/pdf/statistics/v13i11.pdf, page 6.
“Collisions, as a factor contributing to ignition, resulted in 4 percent of all highway vehicle fires”

Does it matter to the driver or the car how it catches fire?

112

+1

Dave G Says

Nov 16th, 2013 (6:47 am)

From the article: Speaking of aluminum, molten aluminum spilled and sent three workers to the hospital Wednesday.

This is an actual Tesla safety issue. 3 people were injured, one of them seriously.

If it explodes into flames during an accident, that would be a lot worse than a fuel line leaking fuel on hot components. That actually happened to us. Around 20 years ago, we had just pulled out of a parking lot when the car started smoking profusely, so I stopped the car and popped the hood. Eventually, the smoke turned into flames. It was a small fire, but they called the fire department to put it out. After that, we towed the car to our local mechanic, and he was able to fix it. Not a big deal.

The Tesla fires were different. Two of these accidents involved running over very large pieces of steel that had just fallen off a truck at highway speed. The other case involved a drunk driver that ran over an embankment, into a wall, then into a tree. In other words, these were all major accidents.

But in all 3 Tesla fires, the fire took several minutes to start, spread slowly, and never reached the passenger compartment. So in this sense, the Tesla fires were more like my experience, where people had plenty of time to get out, and were never in any danger.

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+1

Dave G Says

Nov 16th, 2013 (7:34 am)

250volts: As has been pointed out – everyone of the owners walked away from these fires.

And they all ordered another Model S to replace the one they totaled in the accident.

In other words, the people actually involved in these accidents feel the Model S is safe.

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+2

Ziv Says

Nov 16th, 2013 (9:03 am)

250, I agree with you to some extent, but when your car has a clearance of just 4.5″-5.3″ at speed and the vast majority of cars have an inch or more than that, you won’t see the debris until it is 2 or 3 seconds in front of you (because the car/pickup in front of you will straddle it safely) and you can’t swerve out of your lane because there is traffic to both the left and right of you most of the time.
The difference for the Tesla S is twofold. First, it sits lower than just about every car on the road other than the M5 and a few others. Second, it has a huge point of failure, 5′ wide by 9′ long, on the bottom of the car.
The S is a great car, but they should find a way to reduce the frequency of these incidents. Either raise the highway speed ride height by an inch or use more steel on the pack cover.
They won’t eliminate the problem, but either or both ‘fixes’ would reduce the frequency of the incidents.

On edit:
Here is a patent application by Peter Rawlinson, Tesla’s chief engineer from 2011 in which they are patenting an “improved protection system” for a battery. Is this what Tesla has been using or is it an upgrade to what they have on the S now? I think it is the latter.http://www.patentlens.net/patentlens/patents.html?patnums=US_8286743

250volts:
Seriously I just don’t see the big deal here. We are not going to change the fact that debris is littered all over our roads. How many of us have run over sticks, rocks, tire pieces etc? It is a fact of life.
I use the look and avoid method. No modifications necessary!
…..
Anyway long live Tesla and full steam ahead.

If it explodes into flames during an accident, that would be a lot worse than a fuel line leaking fuel on hot components.That actually happened to us.Around 20 years ago, we had just pulled out of a parking lot when the car started smoking profusely, so I stopped the car and popped the hood.Eventually, the smoke turned into flames.It was a small fire, but they called the fire department to put it out.After that, we towed the car to our local mechanic, and he was able to fix it.Not a big deal.

The Tesla fires were different.Two of these accidents involved running over very large pieces of steel that had just fallen off a truck at highway speed.The other case involved a drunk driver that ran over an embankment, into a wall, then into a tree.In other words, these were all major accidents.

But in all 3 Tesla fires, the fire took several minutes to start, spread slowly, and never reached the passenger compartment.So in this sense, the Tesla fires were more like my experience, where people had plenty of time to get out, and were never in any danger.

I’m aware of the details and yes the severity matters for a host of reasons but that was not the point of my response. The poster I was responding to was intimating the overall Tesla fire risk should only be compared to ICE fire fire risk from striking large large road debris. This appeared nonsensical to me and thus my reply. There are a zillion ways to slice the data if that is the intent. Plenty of cars have burned to a crisp head to toe from the event you described but many more have not. There have also been a lot more Tesla packs sustain hits and some level of damage than the ones that caught fire.

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steve Says

Nov 16th, 2013 (10:58 am)

Loboc:
A car cannot be designed in a public forum or by committee. IF there is a design flaw (I don’t believe there is) “S” can be retro-fitted like other cars.

But, only after simulation and design by real engineers. Sticking a steel plate out front may actually create a cleaver in an accident. What is the effect on crumple zones?

Didn’t we go through this kind of non-issue with Volt? Who was hurt when the government set a Volt on fire accidentally and then couldn’t reproduce the results? GM duly noted that there could be some beefing up for this exact scenario, but, when has this happened in the real world? Never.

All of this buzz around the Tesla ‘problem’ is just that: Buzz.The ‘problem’ (if one exists) is not even defined.

The Tesla hit something in the road and caught fire. A Volt battery caught fire a week or more after a side impact test. It’s a little different and while the occupants where unhurt, it’s not quite a non-problem. Only thing I see that has to be defined is the lower limit of how big a piece of debris has to be to compromise the battery and how much protection is enough.

Dave G: And they all ordered another Model S to replace the one they totaled in the accident.

In other words, the people actually involved in these accidents feel the Model S is safe.

Did Tesla offer these people any kind of compensation towards a new Model S, something hard to turn down?

I don’t think its passenger safety is in question. My concern is with monetary loss. A Tesla is a big investment to make. Insurance rates are bound to skyrocket up if these incidents become too frequent, and Tesla cannot be giving away Model Ses to replace burned up ones.

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+4

WopOnTour Says

Nov 16th, 2013 (1:18 pm)

I personally suspect Tesla is eventually going to improve their pack shielding underneath the car. Going to steel, titanium, or “sandwiched” metal + CF or other composite of sufficient thickness would be a quick fix IMO. Or possibly just thicker aluminum to increase its resistance to puncture from heavy road debris. Raising base trim height or altering the low stops of the automatic lowering system would be another option I suppose, potentially to the detriment of range. Dealing with the costs is another matter but it’s less than 15,000 cars. Other manufacturers, including GM have dealt with far more significant and costly recall expense. Being proactive will be the key. Sticking their heads in the sand just will not cut it IMO.
JMO
WOT

121

Sean Says

Nov 16th, 2013 (1:40 pm)

Unless they do it like Toyota by sending a letter out to there customer if not an e-mail is probably the way to go plus it’s green as using no paper but I wonder what kind of sheet of metal he will use for the replacement hmm?

What do you think he’ll use to make his car safer if it does happened?

122

America1st Says

Nov 16th, 2013 (1:43 pm)

I’ve seen new window tint that is near impossible to shatter, even with a hammer hit. There’s room to improve any car design, and Tesla will have to do something.

123

+1

Noel Park Says

Nov 16th, 2013 (4:58 pm)

WopOnTour: Being proactive will be the key. Sticking their heads in the sand just will not cut it IMO.

#120

America1st: There’s room to improve any car design, and Tesla will have to do something.

#122

Right and right again. +1 to both.

GM retrofitted the early Volts for what was arguably much less of a problem, but they did it to kill the controversy in the crib. Take heed Elon!

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Dave G Says

Nov 16th, 2013 (5:06 pm)

stuart22: Did Tesla offer these people any kind of compensation towards a new Model S, something hard to turn down?

Nobody has mentioned anything like this, so I doubt it.

stuart22: My concern is with monetary loss. A Tesla is a big investment to make. Insurance rates are bound to skyrocket up if these incidents become too frequent…

Remember that the Model S is a high performance car, 0-60 in 4.2 seconds. If anything, that’s what would drive insurance rates higher, not 3 cases of fire with no injuries.

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Pat Says

Nov 16th, 2013 (5:30 pm)

The Model S seems to be built to pass the tests, but not the damage incurred in real life driving. Musk claims that his company can do better then Detroit. For the most part he is correct, but on the other hand, Detroit has a 100 years of experience building cars and tests for things that don’t have to do with Gov or private agency testing. In many cases Detroit has learned the hard way, Tesla will reinvent the wheel on this issue.

126

Bonaire Says

Nov 16th, 2013 (9:02 pm)

WopOnTour:
I personally suspect Tesla is eventually going to improve their pack shielding underneath the car. Going to steel, titanium, or “sandwiched” metal + CF or other composite of sufficient thickness would be a quick fix IMO. Or possibly just thicker aluminum to increase its resistance to puncture from heavy road debris. Raising base trim height or altering the low stops of the automatic lowering system would be another option I suppose, potentially to the detriment of range. Dealing with the costs is another matter but it’s less than 15,000 cars.Other manufacturers, including GM have dealt with far more significant and costly recall expense. Being proactive will be the key. Sticking their heads in the sand just will not cut it IMO.
JMO
WOT

Regarding the detriment to range. Most Tesla drivers are not eco-green, from the looks of things, and spending another 30-100Wh per mile because the car does not auto lower at high speeds doesn’t seem to that big of a deal. Make air ride lowering strictly user-selectable makes some sense as an option over the current automatic mode. But the customer base now knows that the choice of a battery type that is high energy with a propensity for venting with flame is not just a theory but an actual risk should the “armor” (i believe the better word is battery pack external shield) be pierced. Does anyone know the type of aluminum used today? Could it be upgraded or even enhanced somewhat?

127

Koz Says

Nov 16th, 2013 (11:05 pm)

WopOnTour:
I personally suspect Tesla is eventually going to improve their pack shielding underneath the car. Going to steel, titanium, or “sandwiched” metal + CF or other composite of sufficient thickness would be a quick fix IMO. Or possibly just thicker aluminum to increase its resistance to puncture from heavy road debris. Raising base trim height or altering the low stops of the automatic lowering system would be another option I suppose, potentially to the detriment of range. Dealing with the costs is another matter but it’s less than 15,000 cars.Other manufacturers, including GM have dealt with far more significant and costly recall expense. Being proactive will be the key. Sticking their heads in the sand just will not cut it IMO.
JMO
WOT

Other than a couple of thousand Roadster and coil suspension S’es, it is every car they have sold. A far dry from GM or any other major doing significant work on 16,000 vehicles.

The concept I’ve been pushing is a couple inches raise for the lowest air suspension setting with a leading edge protection bar or member that sits a couple of inches lower than the battery’s bottom to take these hits. Expect the software to raise or option to raise the lowest setting for existing cars. Expect the additional hardware for new models at some point.

128

+1

Koz Says

Nov 16th, 2013 (11:09 pm)

Pat:
The Model S seems to be built to pass the tests, but not the damageincurred in real life driving.Musk claims that his company can do better then Detroit.For the most part he is correct, but on the other hand, Detroit has a 100 years of experiencebuilding cars and tests for things that don’t have to do with Gov or private agencytesting.In many cases Detroit has learned the hard way, Tesla will reinvent the wheel on this issue.

Model S has faired pretty well in real world accidents, save two non-injurious heavy road debris incidents. There are plenty of other accident reports one can find with web searches to see real world results.

Remember that the Model S is a high performance car,0-60 in 4.2 seconds.If anything, that’s what would drive insurance rates higher, not 3 cases of fire with no injuries.

Don’t know what categories the insurers use but based on my rate and others I have heard, it seems they are classifying the S as a large sedan or hatchback. At some point they may view it or at least the performance versions as sports models of some sort as you suggest. That would have a significant impact on rates.

130

Sean Says

Nov 17th, 2013 (2:19 am)

One other thing I know how he feels if I were Elon I would be terrified by the media and say what a bunch of lunatics running with there heads cut off like chickens and panicking for no good reason.

But even if so Elon needs to stop being the ostrich and get his game on and fix the problem so he doesn’t have to listen to these no good greedy news people that only care to stir fear into others.

As long as he fixes the problem up and if it doesn’t happen again he won’t have to listen to these no good cow turds!

Let’s hope this is solved before it gets worse I wish this never happened again!

131

Bonaire Says

Nov 17th, 2013 (9:54 am)

Sean, one fix is to use something like LiFEPO4 cells which can be pierced without flame. Currently, such cells come in cylindric form but have less energy per cell. So you would have maybe a 60kWh maximum capacity versus 85 now. Same high speed charging would be possible. Maybe in a few years, Li-S blends could be available which can take a piercing event without flame.

132

+1

Bonaire Says

Nov 17th, 2013 (10:23 am)

Apparently, firmware fix 5.8 disables the auto lowering at speed.

From the tesla forum…

“Several owners over on TMC have confirmed that the active air suspension no longer lowers at speed and will not allow manual lowering at speed.

This “feature” is not included in the release notes and there does not appear to be any official acknowledgement that engineering has made this change.
“

133

+2

ronr64 Says

Nov 17th, 2013 (11:46 am)

It is clear that most Tesla owners do not live where there is snow. The “cow catcher” idea would be dead on arrival for anyone who deals with snow. Although perhaps you could make extra money plowing driveways and parking lots…. lol

I understand cost is an issue but a single plate does not make for good ballistic proof protection. Multiple layers of thinner material would do much more and weigh the same.

134

+1

Dave G Says

Nov 17th, 2013 (3:08 pm)

Noel Park: GM retrofitted the early Volts for what was arguably much less of a problem, but they did it to kill the controversy in the crib. Take heed Elon!

This may be the crux of the issue.

GM sells a lot of cars, and most of them aren’t Volts. In other words, the Volt recall had no noticeable affect on GMs profits.

For Tesla, an unnecessary recall would have a large impact on their profits. For a small company just starting out, it would be a big deal.

America1st: There’s room to improve any car design, and Tesla will have to do something.

Let’s be clear. A design improvement is very different than a recall.

If there’s a known safety issue that has caused a significant number of serious injuries or deaths, then a car maker will generally do a recall.

If there’s a potential safety issue that has not caused a significant number of injuries, a car maker may, or may not do a recall, depending on how it affects their profits, but they will generally look for ways to improve the design safety for future models.

This makes it pretty clear why Tesla is not interested in doing a recall.

135

+2

Dave G Says

Nov 17th, 2013 (3:43 pm)

Sean: One other thing I know how he feels if I were Elon I would be terrified by the media and say what a bunch of lunatics running with there heads cut off like chickens and panicking for no good reason.

Elon has said that Tesla gets way more attention than it deserves, both good and bad.

Sean: But even if so Elon needs to stop being the ostrich and get his game on and fix the problem so he doesn’t have to listen to these no good greedy news people that only care to stir fear into others.

If Tesla did an unnecessary recall:
1) People would mistakenly assume it was a real safety issue.
2) Tesla’s profits would take a huge hit.

Since both 1) and 2) are news worthy, a recall could actually increase the negative media hype surrounding this.

Bottom line: No safety issue = No recall.

136

Koz Says

Nov 17th, 2013 (10:33 pm)

Koz: Other than a couple of thousand Roadster and coil suspension S’es, it is every car they have sold. A far dry from GM or any other major doing significant work on 16,000 vehicles.

The concept I’ve been pushing is a couple inches raise for the lowest air suspension setting with a leading edge protection bar or member that sits a couple of inches lower than the battery’s bottom to take these hits. Expect the software to raise or option to raise the lowest setting for existing cars. Expect the additional hardware for new models at some point.

1/4 to 1/2″ higher not a couple of inches

137

Sean Says

Nov 17th, 2013 (10:58 pm)

Gotcha Dave.G I understand as when GM was trying to fix up the Volt Fox just couldn’t help throwout more negative things about the Volt just to make it seem worse then it actually was.

So yeah if it was nonsense as most likely it’s going to be unless it’s very, very, very, serious then maybe I would take full heed on this issue.

But again who needs the stupid media that can’t hush there mouths up like a bunch of crying two year old’s what a bunch of losers!

Narrator: A new car built by my company leaves somewhere traveling at 60 mph. The rear differential locks up. The car crashes and burns with everyone trapped inside. Now, should we initiate a recall? Take the number of vehicles in the field, A, multiply by the probable rate of failure, B, multiply by the average out-of-court settlement, C. A times B times C equals X. If X is less than the cost of a recall, we don’t do one.
Business woman on plane: Are there a lot of these kinds of accidents?
Narrator: You wouldn’t believe.
Business woman on plane: Which car company do you work for?
Narrator: A major one.

Thanks for the information. Version 5.8 arrived today so I was able to run a test. While the disable occurs at a slow speed, the low setting is allowed while parked so you can creep forward slowly under a low overhang.

I tested it at freeway speed and could never get the car to lower manually. The display occasionally allowed a low setting, however the screen graphic display and vehicle did not lower. Model S could NOT be driven in high or very high mode at speed.

There are roughly 3/8″ thick strips running the length of the battery bottom. Tesla Motors could add 3/8″ shielding between the strips and maintain clearance.

The elimination of the low position may affect range, but it is a small price to pay if the additional clearance prevents damage. It allows Tesla Motors to immediately “fix” all existing Model S vehicles at no charge. That is service to keep the customer smiling.

My only issue with these numbers are the 150k ICE fires represents a huge range and age of cars. I guarantee if you looked at cars in the same age range of the Model S the number of fires for ICE cars is a lot lower. Just use the Leaf and Volt as examples – more vehicles on the road, but less fires. So I would look at it from the perspective that for some reason the Model S has more incidents of fires than like vehicles.

141

jeffhre Says

Nov 18th, 2013 (9:38 am)

bobchr:
By the way, everyone keeps pointing out no one was hurt. IS the proper course of action to wait until some one is or be more proactive?

From a business perspective that makes a lot of sense.

However, from an engineering perspective, and with no pun intended, the fact that no one was hurt is not an accident. Therefore proper actions appear to have been taken during the design and manufacturing of the car. It should not be surprising that their is admiration for that achievement. Even though from a public relations perspective, more can clearly be done.

My only issue with these numbers are the 150k ICE fires represents a huge range and age of cars.I guarantee if you looked at cars in the same age range of the Model S the number of fires for ICE cars is a lot lower.Just use the Leaf and Volt as examples – more vehicles on the road, but less fires.So I would look at it from the perspective that for some reason the Model S has more incidents of fires than like vehicles.

That is about as scientific as saying newer cars are clearly more dangerous than older ones because the new Jaguar Dick Van Dyke was driving burned to the ground.

In any case all Tesla fires, so far, have initiated after impacts. Most of the car fires reported at large are due to electrical system shorts. Shorts that occur whether or not their was an accident or major impact to the vehicle.

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merlin Says

Nov 18th, 2013 (11:53 am)

James: Mark Z,Comment #4. Well said, and I totally agree. You have a balanced way of looking at the situationIMO.Look – I believe it is the best car in the world. It’s not perfect. Yet I believe it’s not“dangerous” – and I’ll stick to that until proven otherwise. The fact the car lowers itself was a big plus for me, as I suggested GM do this with Volt – it really adds to efficiency on the hwy I will admit that I did not consider road debris, yet I’m positive Tesla’s engineers did. They believed their safety checks and balances were adequate. I keep wondering if Kevlar may be the answer, or simply issuing a software update todisengage the suspension-lowering feature. I lowered my 2nd gen Prius 5/8″ and saw a dramatic result in hwy mileage with no road debris puncturing incidents in 3 years. I do hit curb cuts diagonally when possible and have rubbed the bottom even when the Prius was stock height. My Volt has yet to bottom out even on some tricky angled road-to-entryway transitions.CHARGE! ,James

My Honda Fit is lowered about 1 1/2″. It rides about 5 1/2″ above the pavement (similar to Tesla ride height). Road debris is bouncing around up in there in ways that are much more noticeable than at stock height. I nose dive into dips occasionally caused by bad road seams or whatever (I suspect my coilover setup is not quite stiff enough though). Because of this kind of experience I would imagine that the cow-catcher type solution would not work at all. It would have to be hinged or be able to move independent of the bumper/frame so that it doesn’t get ripped off on impacts and bounce up out of the way. But it would have to be stiff enough/strong enough to stay down long enough to deflect the road hazard. Those two things don’t really go together well.